Shock absorber



March 24, 1925, l

J. WATSON SHOCK ABSORBER Filed Sept. 5, .1922

Mimi

fa 7:4 SWAT@ ow -M far/15's i Figure 2.

Patented Mar. 24, 1925.

UNITED STATES irtrsrrr OFFICEV l JAMEsWArsoN, or Los ANGELES, CALIFORNIA.

Application ined september 5, 1922. seriai No. 586,060.

absorbed instead of being transmitted tothe An object of the invention is to provide a shock absorber to retard or eliminatethe free bounding movementv of the'vehicle wheel without transmitting 'the shock to the vehicle body. 1

A further object is the provision of a shock absorber whichrwill effectivelyprevent the 'swiftl and objectionable recoil' or rebound of the `vehicle springs', but which will allow the springs to gradually and gently regain their positionafter being com-` pressed. l y p Another object is to provide a shock absorber of the liquid displacement type in which they are no ltight seating valves,v` or springs, and including a control eleinentconsisting of a freelymovable body which while regulating the action of the device need not contact the parts'with which it cooperates to eect lsuch control. l

A further object is to provide a' shock absorber which will be neat'and attractive 'in appearance, which will be strong and durable in use,.and which of moving parts.

has aminim'um Various otherpobjects and advantages will be more fully apparent from the' following description of the Iaccompanying drawings,

which form a part of this disclosure, and

which illustrate a preferred form of embodiment of the invention. Y

Of the drawings:

' V Fig. l is an elevation of part of an Vautomobile structure and its springs, showing my shock absorber in position.

Fig. 2 is an enlarged central vertical section through the shock absorber.`

Fig. 3 is a plan section on line 3%-3 ,of

In'the drawings, l designates a portion vof the automobile frame andi?.j designates an elliptic spring, the upper half being connected to the frame vl and the lower half to the axle 3. It should not be presumed that the device hereinafter' described is applicable only to this type of spring, because, in lfactfthespecific type'of spring Vis not in any way a controlling factor, and any other type would be equally assisted by the device of the present invention.

ln practicing my invention I' provide a closed cylinder and a piston element working in the cylinder; I also provide a port establishing communication from one side to the other ofthe piston, together with choking means consisting of a memberfcarried loose in the port, the member being Y smaller, or of'less areathan the port-'and operating to restrict the port during the flowin onerdirection; in this operation `this choking means, in the otherV direction of flow, moves to a point where the `flow through theA port is substantially -unrestricted. Y

The shock Yabsorber structure comprises `a closed cylinderA ihaving a universal connection' at its lower end for connection'to the 'medialrigid portion of the lower half of the spring, and a piston element includinga piston head 7 slidable within the cylinder and a piston rod 8 extending through a packing box 9 in the wall of the cylinder, the rod being provided at its upper end with a universal connection lOKjo-ining it to the medial rigid portion of the upperhalf of the spring. Vhile4 I have shown the shock absorber interposed between the two halves of the spring it will be evident that this is only for. the purpose ofillustrating one specific installation, it being yreadily understood that the device may beinterposed at otherv locations between the running gearV and the body. p Y Y The piston head 7 has a suitable piston ,ring l1 or other type of'packing and the cylinder is filled with liquid, preferably oil.

' `ThepistonV rod 8 is fixed tothe'piston head,

preferably by being screw-threaded therethrough with a lock nut 12 engaging its lower end and clamping the head rigidly in place. `I provide the piston with means establishing communication between the ends of the cylinder and operating to permit a relatively free iow of the oil onthe down.

' ward movement ofthe vehicle body, but I lprovide a choking device for causing a restriction of the iiow on the up movement of Y the body. For this purpose the yrod has` a of the piston head 7and the walls ofthe rod have transverse openings 14 communicating with said bore and with the cylinder on' the upper side or' the piston head, the bore 13 and openings 14 forming AaV permanently open port establishing communication from on side to the other oi?. the piston. The kbore 13 extends upwardly beyond the openings 14 to form a pocket extension 15 and posi@ tioned within the bore is a choking device in the form of a control ball 16 of a diameter which is less than that of saidbore, a transverse pin17 carried by the rod, preventing the ball 16 from falling out ofthe'bore.

With the mechanism in the position shown in Fig. 2,/it Ywill be assumed that the vehicle wheel strikes an obstacle, such as a railroad crossing, for example; the effect of striking the obstacle is to force the axle upwardly and to compress the spring. At the shame timethe lower end of the Cylinder 5 rises towards the piston head 7 V'lhis will cause theliquid to force the ball up# wardly into the vpocket l'leaving the port entirely unrestricted by theball. This allows the displacement or' the liquid from lbelow the piston `head to above the piston head at a speed depending upon the maximum area of the bore 13-and openings 14.

The energy stored in the vehicle springs now expends itself infprojecting thevehicle body upwardly, thus reversing the relative movement of the cylinder and plnn'ger. The movement or the `plunger is in Ythis instance upward relative to lthe cylinder and during the first portion or such movement the control balllG returns to its normal position to rest on the stop pin 17. Thewport Y is now restrictedto an Varea equal tothe difference between the diameter' or the ball and that or thebore 13, and the owof thc oil through the port from above the pistou head 7 is proportionately decreased. In this mannerthe rebound is absorbed slowly so that the shock occasioned by the obstacle encountered, is not transmitted ,to thelvehicle body. Y

It is to be noted that the control ball yis not required to seat or to engage the walls or the bore in effecting a control for the port, and in this regard cannot be vconsidered as a valve in the ordinary use ofthe term Ybut ratheras a clicking means for restricting the return flow or the liquid. Also attentionv is directed to the] simplicity and Y strength of the construction which has only three inoving'part's and is entirely devoid lo:p

VVVsprings.

Having no valve seats or close working parts there 1s no danger oi the device 'railing to work by reason of impurities ci' sediment in the oil.

The ball 16 is preferably of a specific gravity slightly greater than the liquid in the cylinder so as to always seek its normal -positiononthestop pin 17 excepting when forcednpwardly by the kupward low or' the 7 "liduid V'through the port.

`the form of device herein illus# trated and described is well adapted to tulil the objects primarily st ated, it is .to be understood that the invention is not to be limited in this regard, .for it susceptible of embodiment infva'rious other forms,` all vcollflin'gwithin the scope of the vfollowing claims. y

I claimt f 1. ,A shock absorber.comprising a lclosed cylinder, a piston Aelement in the ,cylinder andhaving a`'permanently `openV port establishing communication from'fone side to the other ,of lthe piston, and choking means consis'ting of a. membercarried .loose in the port, or'less area than the port, 4o creating' to restrict said port during the ow oft ,the contents of the cylinderlhrough it in one .direetioniand Aautoinatically movable the lflowof said contents in ya reverse direction to aposition .permitting an unrestricted flow through the port.l i i 2. A ,shockablsorber comprising a closed cylinder,"a piston element in the cylinder having a .permanently open port 'establisliing communication from one side toV the other ofthe pistomfsaidfport haying a pocket extension, and a control element restrcting. said port during vthe flow or the contents of the cylinder through port in one direction and automatically movable into'the ,pocket ertensionfby the flow of said i contents in a reversedirection to' permit an unrestricted .How through the port.

shock absorber ccmprising Va' closed cylindeig. a piston element in the cylinder and having a permanently open port festablishing communication from one side to the other of the piston, and a choking means in the ferm ef ball Carried loose in the port @Gratins t0 restrict .Said port'durngfthe :How of the contents of the cylinder through said port in one direction .and automatically movable the flower saidcontents in are-verse A 'direction te permit" an" unrestricted .flow through the portf, said control means having a greater speciicfgravity than said 7cylinder contents. l' l 4. A shock absorber cemprising a closed cylinder,` a piston elementuin the cylinder and having a permanently open port estab-v lishing communication lfroinone side Ptol the other of the piston, said port iliaving a pocket extension', and va control: ball in the port restricting'fsaid portduring' the ^flo-w ofthe contents of the cylinder through said port in one direction and automatically Y* 'rinotable` int@ Said Pocket' eXt'nSiOn by" the 'ilwf` of saidV contents lin va reverse' direction to permit an unrestricted iiow through the port.

- 5. A shock absorber comprising a closedI ment having a permanently open axial vport extending from one sideof the piston upwardly into the rod and communicating With the cylinder on Vthe opposite side ot the piston, said port having a pocket extension, and a control member in the port restricting said port during the flow of the cylinder contents through said port in one direction and automatically movable into said pocket by the flow ofsaid contents in a reverse direction to permit an unrestricted flow through the port. Y

6. A shock absorber comprising a closed cylinder', a piston velement in the cylinder and including a piston head anda piston rod extending through and attached to said head and extending through the wall of the cylinder, said rod having a permanently open axial bore extending upwardly from the lower end of the rod on one side of the` piston head and transverse openingsv com-4 municating With said bore andwith the cylinderfon the upper side of the piston head, said openings having a combined area equal to the area of the bore, and the bore extending above said openings to provide a pocket extension, a control ball in the bore restricting the flow of the cylinder contents 'from the upper to the lower sides of the pistonV head and automatically movable into said pocket to permit an unrestricted reverse flow of saidvcontents, and means preventing said ball from dropping from said bore.

Signed at Los Angeles, Calif., this 19th 40 y day of August 1922.

JAMES WATSON. 

